U.S. Pat. No. 4,705,007 describes a method according to which phases with and without tank venting (namely, tank-venting phases and base-adaptation phases) alternate in a fixed raster. 5 minutes are provided for the tank-venting time span and 1 minute is provided for the base-adaptation time span. In practice, the first time duration is more likely to be somewhat shorter and the second somewhat longer.
The duration of the tank-venting time span together with the characteristic variables of the tank assembly and of the corresponding engine determine the size of the adsorption filter in which fuel vapor is adsorbed from the tank. These variables also determine the diameter of the tank-venting valve with the aid of which the adsorption filter is purged with air. The size of the adsorption filter and the cross section of the tank-venting valve must be so dimensioned that, even for the largest possibly occurring fuel vapor quantity, essentially all fuel vapor can be adsorbed during the base-adaptation time spans and can again be desorbed during the tank-venting time spans.
In the technology, the problem generally is present to operate arrangements according to such methods and to so configure the arrangements that the components are used in the most purposeful manner possible. This problem applied correspondingly also to methods and arrangements for carrying out phases with and without tank venting during operation of an internal combustion engine with a tank-venting assembly.